1. Field of the Invention
This invention relates generally to water well apparatus and, more specifically, to a Well Cleaning Method and Apparatus using detonating cord having Additional Reliability and a Longer Shelf Life.
2. Description of Related Art
The present invention is an improvement on U.S. Pat. No. 3,721,297 for Method for Cleaning Wells, and on U.S. Pat. No. 4,757,863 for Well Cleaning Method and Apparatus. The '863 patent sought to, and in fact did, resolve several problems associated with the design of the '297 patent. The method and apparatus disclosed by the '863 patent utilized a design that was less costly and less complex than that disclosed in the '297 patent. Furthermore, the device of the '863 patent is compliant with government transportation regulations that prohibit the shipping of armed explosives. As a result of these improvements, the new device met with continuing and widespread success.
Despite the sustained success of the revised device, as additional experience has been gained with the device and method of the '863 patent, other deficiencies have been recognized. First, it has become desirable to extend the shelf life of the device, so that long periods of storage (either at the supplier or end-point user) will not make the device unreliable. Second, there has been some evidence of non-sequential detonation in adjacent explosive assemblies; while this is not a safety problem, it can reduce the overall effectiveness of the method and device.
What is needed, therefore, is an improved well cleaning apparatus that has a longer shelf life and more reliably sequential detonation.